Millions of years of anecdotal evidence are certainly enough proof of this fact for most of us, but we can thank scientists at the California Institute of Technology and the University of California at Los Angeles for validating our inherent knowledge.

The researchers studied brain activity in 41 people and found that the neurons in a part of the brain called the amygdala became very active when the participants were shown pictures of animals. Even photos of people didn’t produce the same level of stimulation.

What is the amygdala? It’s a pair of almond-shaped cell clusters deep within the brain. Its job is to form and store memories associated with emotional events.

Because the amygdala has a strong role in fear conditioning, the researchers expected higher levels of response to hazardous animals like spiders and snakes — but it turned out that all kinds of animals, from the cute to the ugly to the downright scary, stimulated the tiny lobes of brain tissue. And unlike most amygdala-controlled responses, the response to animals doesn’t seem to be connected to the emotional contents of the pictures.

Go figure.

The study noted that the intense brain activity triggered by pictures of animals “may reflect the importance that animals held through our evolutionary past.”

Maybe we developed that instinctive response to animals so we could bypass the logic-oriented “let’s mull this over” part of the brain and instantly differentiate among animals that are friends, predators, or prey. Being able to react quickly was probably one key to the survival of the human race.

It’s kind of nice to know that there’s a reason to have a stronger response to a cat than to another person. Hooray for my amygdala and its role in making me a cat lover from the moment I drew my first breath!